JPH05298852A - Tape cassette and its production and molding die - Google Patents

Abstract

PURPOSE:To simply and easily form the tape cassette and to prevent the dislodgment of a window part by inserting a resin layer having a low modulus of elasticity between resin layers on both sides and integrating the intermediate layer and the window part for the remaining amt. of a tape with a transparent resin. CONSTITUTION:The upper and lower cassette halves 2, 3 are formed of a resin material 7 having a three-layered structure consisting of the resin layers 4, 5, 6. The intermediate resin layer 5 and the window part 8 for visually checking the remaining amt. of the tape are integrally formed of the transparent resin. The resin layers 4, 6 are formed of ABS and the resin layer 5 is formed of an elastomer having the lower modulus of elasticity than the modulus of elasticity of the resin layers 4, 6. The resin layer 5 is then so coated as to hold the resin layer 5 with the resin layers 4, 6 exclusive of the parts for the window part 8 for visually checking the residual amt. of the tape, by which the cassette halves 2, 3 are formed. A window frame 9 is templated in the resin layer 4 and a transparent thermoplastic resin is packed within the window frame 9, by which the window part 8 is formed integrally with the resin layer 5. The problems, such as peeling of the resin layer 5 and dislodgment of the window part 8, are then eliminated and since there is no need for considering the compatibility between the resin layers and, therefore, the range for selecting the resins is widened.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tape cassette provided with rigidity and vibration damping by forming a cassette half with a multi-layered synthetic resin material, a method of manufacturing the same, and a molding die.

[0002]

2. Description of the Related Art In a magnetic recording tape cassette, for example, a compact tape cassette, the cassette half vibrates due to the vibration generated from the deck and the sound pressure generated from the speaker, which adversely affects the running of the magnetic tape and deteriorates the sound quality. ..

Therefore, as shown in FIG. 7, an inner layer 10 of a low elastic modulus synthetic resin is formed on the inner surface of an outer layer 101 of a high elastic modulus synthetic resin.
A tape cassette using a so-called two-layer cassette half in which 2 is injection-molded and vibration is absorbed by the low elastic modulus synthetic resin inner layer 102 has also been developed.

Reference numeral 103 is a transparent window portion for recognizing the remaining tape amount.

[0005]

By the way, the above-mentioned conventional 2
The layered tape cassette has the following problems.

(1) In order to integrate the outer layer 101 and the inner layer 102 so that the outer layer 101 and the inner layer 102 are not easily separated from each other, the compatibility of the synthetic resins forming the outer layer 101 and the inner layer 102 must be considered. But for this,
The type of synthetic resin used for the outer and inner layers 101, 102 is limited.

(2) Due to the presence of the inner layer 102 of the low elastic modulus material, the mechanical strength, particularly the rigidity, of the cassette half is weakened.

(3) Since the window frame is formed by cutting out a part of the outer layer 101 and the transparent resin is injected into the window frame to form the window portion 103 for recognizing the remaining tape amount, the window portion 103 is formed. The compatibility between the transparent resin and the resin of the outer layer 101 becomes a problem, and the window portion 103 is likely to drop from the window frame.

The present invention has been made for the purpose of solving the above conventional problems.

[0010]

The present invention includes first, second and third embodiments.
A tape cassette comprising three resin layers of a third resin layer, wherein a cassette half is made of a resin material having a multi-layer structure in which a resin layer having a high elastic modulus on both sides covers an intermediate resin layer having a low elastic modulus. The intermediate resin layer and the window for recognizing the remaining tape amount were integrally formed of transparent resin.

[0011]

[Function] Since the intermediate low-elastic-modulus resin layer is covered with the resin layers on both sides and the low-elastic-modulus resin layer is wrapped with the resin layers on both sides, the resin layers on both sides and the intermediate resin layer are compatible with each other. Even if it is not present, peeling of the intermediate resin layer can be prevented.

Further, since the surface of the intermediate low elastic modulus resin layer is covered with the elastic layer having a higher elastic modulus than this, the mechanical strength (rigidity) of the cassette half is increased as compared with the conventional two-layer structure. be able to.

Further, when forming the intermediate resin layer,
Since a window for recognizing the remaining tape amount is formed integrally with this,
Since the window portion can be easily formed and the intermediate resin layer and the window portion are inseparable from each other, there is no problem of the window portion coming off.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The tape cassette of the present invention, its manufacturing method, and a molding die used in the manufacturing method will be described below.

FIG. 1 is an exploded perspective view of a tape cassette 1 of the present invention, which comprises upper and lower cassette halves 2 and 3.

Then, the upper and lower cassette halves 2,
3 is formed of a resin material 7 having a three-layer structure including first, second and third resin layers 4, 5 and 6, and the intermediate second resin layer 5 and a window portion for observing the remaining tape amount. 8 and 8 are integrally formed of transparent resin.

The first and third resin layers 4 and 6 are made of ABS resin, and the second resin layer 5 is made of an elastomer having a lower elastic modulus than the first and third resin layers 4 and 6. ..

The first and second resin layers 4 and 6 except for the window portion 8 for recognizing the remaining tape amount
The cassette halves 2 and 3 are formed by covering the resin layer 5 so as to sandwich it.

Next, a method of manufacturing the cassette halves 2 and 3 will be described.

The manufacture of the cassette halves 2 and 3 is shown in FIGS.
This is performed in the next step using the molding die 11 as shown in FIG.

First, as a first step, an ABS resin is injected as shown in FIG. 3 to form a first resin layer 4 in which the window frame 9 is die-cut.

Next, as a second step, as shown in FIG. 4, a transparent elastomer having a lower elastic modulus than that of the first resin layer 4 is injected onto the first resin layer 4, thereby the first resin layer 4 is injected.
By forming the second resin layer 5 which is slightly smaller than the resin layer 4 and filling the transparent thermoplastic resin in the window frame 9 provided in the first resin layer 4, it is possible to confirm the remaining tape amount. The window portion 8 is formed integrally with the second resin layer 5.

Further, as a third step, as shown in FIG. 5, by injecting the ABS resin of the same quality as the first resin layer 4, the portion other than the window 8 for recognizing the remaining tape amount is removed. A third resin layer 6 which is slightly larger than the second resin layer 5 is formed, and a second resin layer 6 is formed between the third resin layer 6 and the first resin layer 4.
The resin layer 5 is adhered, the peripheral portion of the third resin layer 6 is welded to the first resin layer 4, and the second resin layer 5 is covered with these first and third resin layers 4 and 6. Thus, the cassette halves 2 and 3 in which the window portion 8 for recognizing the remaining tape amount is provided integrally with the intermediate second resin layer 5 are manufactured.

Next, the molding die 11 will be described. The molding die 11 includes a fixed die 12, a movable die 13, and first, second, and third slide members (cores) 14 slidably attached to the fixed die 12 and the movable die 13. ，
15 and 16 are provided.

Then, as shown in FIG. 3, the fixed mold 1
2, movable mold 13, and first, second and third slide members 1
4, 15 and 16 form a cavity (space) for forming the first resin layer, and the ABS resin is injected into the cavity from the first resin injection port 21 for forming the first resin layer. It is adapted to form layer 4.

After forming the first resin layer 4,
The first, second and third slide members 14, 15 and 16 are slid to form a second resin layer and a cavity for forming a window portion for recognizing the remaining tape amount, and a second cavity is formed in the cavity.
By injecting a transparent elastomer from the second resin injection port 22 for forming the resin layer, the second resin layer 5 and the window portion 8 for observing the remaining amount of the tape are formed integrally with the second resin layer 5.

After forming the second resin layer 5 and the window 8 for recognizing the remaining tape amount, the second slide member 15 is slid to form a cavity for forming the third resin layer, and the cavity is formed. The third resin layer 6 is formed by injecting the same ABS resin as that of the first resin layer 4 from the third resin injection port 23 for forming the third resin layer.

The first resin injection port 21 is provided in the movable mold 13.

The first resin injection port 21 is provided with a first resin supply pipe 31 provided in the fixed mold 12, and a first plate for supporting the resin supply pipe supporting the tip of the first resin supply pipe 31. A second plate 34 having a resin flow path 33 continuous with the first resin supply pipe 31 and one end surface of the second plate 34. Through the third plate 36 having the resin flow path 35 connected to the path 33,
It is connected to a third resin (ABS resin) supply cylinder.

The second resin injection port 22 is provided in the first slide member 14.

The second resin injection port 22 is provided on one end side of the second resin supply pipe 41 attached to the first slide member 14, and the other end side of the second resin supply pipe 41 is on the first plate. It is slidably inserted in a pipe insertion hole 42 provided in 32.

The second resin supply pipe 41 includes the first plate 32, the second plate 34, and the third plate 36.
Via the resin flow paths 43, 44 and 45 respectively provided in
It is connected to a second resin supply cylinder (not shown).

The third resin injection port 23 is provided in the second slide member 15.

The third resin injection port 23 is provided on one end side of the third resin supply pipe 51 attached to the second slide member 15, and the other end side is a pipe insertion hole 52 provided on the first plate 32. Is slidably inserted into.

The third resin supply pipe 51 includes the first plate 32, the second plate 34, and the third plate 36.
Via the resin flow paths 53, 54, 55 respectively provided in
It is connected to first and third resin supply cylinders (not shown).

Resin flow paths 33, 5 of the second plate 34
4 are provided with first and second electromagnetic on-off valves 61 and 62, respectively. The first electromagnetic on-off valve 61 is opened, the second electromagnetic valve 62 is closed, and the first and third solenoids (not shown) are provided. When the molten ABS resin is supplied from the resin supply cylinder, the molten ABS resin is injected into the cavity from the first resin injection port 21 through the resin flow path 33 and the first resin supply pipe 31.

Contrary to the above, the first electromagnetic on-off valve 6
1 is closed, the second solenoid on-off valve 62 is opened, and the first and second
If the molten ABS resin is supplied from the resin supply cylinder, the molten ABS resin will flow through the resin flow path 54 and the third resin supply pipe 51.
Through the third resin injection port 23 to be injected into the cavity.

Next, the first and second slide members 14 and 15
The first and second slide member operating mechanisms 71 for operating the will be described.

The first and second slide member operating mechanism 71
Is a first spacer plate holding body 72 provided on one end side of the first slide member 14 so as to face the first plate 32, and the second slide member 1
The second spacer plate sandwiching body 73, which is provided on one end side of No. 5 so as to face the first plate 32.
And a spacer plate 74 slidably interposed between the first and second spacer plate holding bodies 72 and 73 provided on the first and second slide members 14 and 15 and the first plate 32. Is equipped with.

The spacer plate 74 includes
Two types of thick-walled portions to be held between the spacer plate contact surface 72a of the first spacer plate holding body 72 and the first plate 32 (hereinafter, the thick portion is referred to as The first attached portion is referred to as a first attached portion, and a thin portion is referred to as a second attached portion) 75 and 76.

Further, the spacer plate 74 is held between the spacer plate contact surface 73a of the second spacer plate holding body 73 and the first plate 32, and is attached to the spacer plate 74 with three different thicknesses. Part (hereinafter, the thickest part is referred to as the third attached part, the middle part is referred to as the fourth attached part, and the thinnest part is referred to as the fifth attached part) 77, 78 ，
79 is provided.

Then, the first attached portion 75 is the spacer plate contact surface 7 of the first spacer plate attached body 72.
It is sandwiched between 2a and the first plate 32, and the third attached portion 77 is sandwiched between the spacer plate contact surface 73a of the second spacer plate attached body 73 and the first plate 32. At times, as shown in FIG. 3, the first, second and third slide members 14, 15, 16 and the movable mold 1 are
3. The fixed mold 12 forms a cavity for forming the first resin layer.

From the state of FIG. 3, the spacer plate 74 is located above the drawing, that is, the third attached portion 77 is the spacer plate contact surface 73a of the second spacer plate attached body 73.
And the first plate 32 are slid in the direction of coming out from between the first plate 32 and the second attached portion 76, which is moved to the side of the spacer plate contact surface 72a of the first spacer plate attached body 72, and the fourth portion. When the attached portion 78 moves to the side of the spacer plate contact surface 73a of the second spacer plate attached body 73, the first slide member 14 and the second slide member 15 move to the right in FIG. And the spacer plate contact surface 72a of the first spacer plate attached body 72 contacts the second attached portion 76, and the spacer plate contact surface 73a of the second spacer plate attached body 73a.
Comes into contact with the fourth attached portion 77, and as shown in FIG. 4, the second resin layer and the cavity for forming the window portion for recognizing the remaining tape amount are formed.

From the state shown in FIG. 4, the spacer plate 74 is
4 further slides upward in FIG.
When 9 moves to the side of the spacer plate contact surface 73a of the second spacer plate holding body 73, the second slide member 15 moves the spacer plate holding surface 73a.
Slides until it adheres to the fifth adhesive portion 79, and the cavity for forming the third resin layer is formed as shown in FIG.

The third slide member 16 is used to form the window frame 9 on the first resin layer 4 by punching when the first resin layer 4 is formed.

The third slide member 16 is a movable mold 12
When the first resin layer 4 is formed, it is pressed by a third slide member operating mechanism (not shown) and protrudes into the cavity.

After the first resin layer 4 is injection-molded, the third slide member 16 is extracted from the first resin operation 4, so that the window frame 9 is die-cut.

All the driving operations of the molding die 11 such as the first and second slide member operating mechanisms 71 and the third slide member operating mechanism are automatically controlled by a controller (not shown).

The molding die 11 of the embodiment has the structure as described above, and in the state shown in FIG. 3, the first electromagnetic on-off valve 61 is open and the second electromagnetic on-off valve 62 is closed. The molten ABS resin of the first and third resin supply cylinders is injected into the cavity from the first resin injection port 21,
The resin layer 4 is formed.

When the first resin layer 4 is formed,
The second slide member operating mechanism 71 and the third slide member operating mechanism operate, and the first, second, and third slide members 1
4, 15 and 16 move to form a second resin layer and a cavity for forming a window portion for observing the remaining amount of the tape, and the transparent molten elastomer of the second resin supply cylinder is fed from the second resin injection port 22 to the cavity. The second resin layer 5 and the window portion 8 for observing the remaining amount of the tape are integrally formed by being injected into the inside.

When the second resin layer 5 and the window portion 8 for recognizing the remaining tape amount are formed, the first and second slide member operating mechanisms 71 are operated and only the second slide member 15 is moved,
A cavity for forming the third resin layer is formed, the second electromagnetic opening / closing valve 62 is opened, the first electromagnetic opening / closing valve 61 is closed, and the molten ABS resin in the first and third resin supply cylinders is the third resin. Injected into the cavity from the inlet 23,
The resin layer 6 is formed.

The ABS formed as described above
Comparison of vibration damping and rigidity of a three-layer cassette half consisting of resin / elastomer / ABS resin with a conventional ABS resin single-layer cassette half and ABS resin / elastomer two-layer cassette half. The results shown in Fig. 6 were obtained, and it was demonstrated that the cassette half having a two-layer structure is superior in both vibration damping property and rigidity.

In the embodiment shown in the drawings, ABS resin is used for the first and third resin layers 4 and 6, and an elastomer is used for the second resin layer 5 and the window portion 8 for recognizing the remaining tape amount. As shown, a thermoplastic resin such as GP-PS (general-purpose polystyrene), AS, or PC is used for the first and third resin layers 4 and 6, and the second resin layer 5 and the window portion for observing the remaining tape amount are used. 8 for H
You may use thermoplastic resins, such as I-PS, ABS, and PP.

Although the third slide member 16 is used to form the window frame 9 in the first resin layer 14 by die-cutting in the embodiment shown in the drawing, the third slide member 16 may be omitted and The window frame 9 may be die-cut with the first slide member 14.

Also, the first and second slide member operating mechanisms 7
No. 1 is not limited to that of the embodiment, and any point can be used as long as it can reliably operate the first and second slide members 14 and 15 with a simple structure.

[0056]

The present invention has the following effects.

(1) In the tape cassette of the present invention, the intermediate second resin layer is covered with the resin layers on both sides (upper and lower) to form the second intermediate layer.
Since the resin layer is in a so-called wrapped state, there is no problem of peeling and it is not necessary to consider the mutual compatibility of the resin layers, so it is possible to expand the selection range of usable resins and to further improve vibration damping performance and rigidity. It becomes possible to provide an excellent tape cassette.

Further, since the second resin layer and the window portion for recognizing the remaining tape amount are integrally formed, it is possible to eliminate the problem of the window portion coming off.

(2) After the first resin layer is injection-molded by the tape cassette manufacturing method of the present invention, the second resin layer and the window portion for recognizing the remaining tape amount are made of transparent resin on the first resin layer. By a simple operation of injection molding and further injection molding the third resin layer thereon, it is possible to form a cassette half having a transparent window portion for recognizing the remaining amount of the tape.

(3) In the molding die of the present invention, since the first and second slide members are provided with the second and third resin injection ports, the second slide member is slid while the second slide member is slid. The transparent molten resin is injected from the resin injection port, the second resin layer and the window for recognizing the remaining amount of the tape are slid, and the molten resin is injected from the third resin injection port while sliding the second slide member. The three resin layers can be formed easily and easily.

[Brief description of drawings]

FIG. 1 is a partially cutaway exploded perspective view of a tape cassette of the present invention.

FIG. 2 is an enlarged view of part A in FIG.

FIG. 3 is a sectional view showing a formation state of a first resin layer.

FIG. 4 is a cross-sectional view showing a formation state of a second resin layer and a window portion for observing the remaining amount of tape.

FIG. 5 is a cross-sectional view showing a formation state of a third resin layer.

FIG. 6 is a characteristic diagram.

FIG. 7 is a perspective view of a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Tape cassette 2, 3 ... Cassette half 4 ... 1st resin layer 5 ... 2nd resin layer 6 ... 3rd resin layer 7 ... 3 layer structure resin material 8 ... Window part for tape remaining amount visual recognition 11 ... Molding metal Mold 12 ... Fixed mold 13 ... Movable mold 14 ... First slide member 15 ... Second slide member 16 ... Third slide member 21 ... First resin injection port 22 ... Second resin injection port 23 ... Third resin injection port

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification number Office reference number FI technical display location G11B 23/087 C 7177-5D // B29K 55:02 105: 32 B29L 9:00 4F 31:34 4F

Claims (3)

[Claims] 1. A cassette made of a resin material having a three-layer structure comprising three resin layers of a first resin layer, a second resin layer and a third resin layer, and a resin layer having a low elastic modulus in the middle between both resin layers. A tape cassette having a half-shape, wherein the intermediate resin layer and a window for recognizing the remaining tape amount are integrally formed of transparent resin. 2. The first resin layer is injection-molded and then the first resin layer is formed.
A transparent second resin layer is injection-molded on the resin layer, a third resin layer is further injection-molded on the transparent second resin layer, and a third resin layer is injected between the first resin layer and the third resin layer. A method of manufacturing a tape cassette, characterized in that a transparent second resin layer is interposed and a window for visually recognizing the remaining tape amount is formed integrally with the transparent second resin layer. 3. A fixed mold, a movable mold, and first and second slide members provided on one of the fixed mold and the movable mold. The first resin layer is injection molded. After that, the first and second slide members are slid to make a second
A molding die in which a resin layer and a window for recognizing the remaining amount of the tape are injection-molded, the second resin layer is injection-molded, and then the second slide member is further slid to injection-mold the third resin layer. In the mold, a resin injection port for forming a second resin layer for injection-molding the second resin layer and a window for recognizing the remaining tape amount is provided in the first slide member, and the second slide member is provided with the resin injection port. Third
A molding die provided with a resin injection port for forming a third resin layer for injection-molding a resin layer.